Potential sources of polyunsaturated fatty acids

All-Union Scientific-Research Institute of the Technology of Blood Substitute and Hormone Preparations, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 4, p. 592, July–August, 1988.     

Isolation and structural analysis of the cyclic fatty acid monomers formed from eicosapentaenoic and docosahexaenoic acids during fish oil deodorization

Long-chain polyunsaturated fatty acids (LC-PUFAs) present in fish oils are thermolabile molecules. Among the degradation reactions encountered, thermal cyclization occurs during refining or other heat treatments. Numerous studies have been carried out in the past to quantify and determine the structures of cyclic fatty acid monomers (CFAMs) formed from oleic, linoleic and linolenic acids in heated vegetable oils. Recently, much attention have been given to LC-PUFAs due to their potential health benefits. However, data on quantification of CFAMs formed from these fatty acids, such as eicosapentaenoic acid (EPA, cis-5, cis-8, cis-11, cis-14, cis-17 20:5) and docosahexaenoic acid (DHA, cis-4, cis-7, cis-10, cis-13, cis-16, cis-19 22:6), the two main LC-PUFAs in fish oils, are scarce. In the present study, structural analyses of CFAMs formed from EPA and DHA during the deodorization of fish oil are presented. Fish oil sample was deodorized at 250 degrees C for 3 h under a pressure of 1.5 mbar in a laboratory deodorizer. The CFAMs formed during heat treatment of fish oil were isolated by a combination of saponification, esterification, urea fractionations and column chromatography. Structural analyses of C20- and C22-CFAMs were achieved by gas-chromatography electronic-ionization mass-spectrometry (GC-EI-MS) of their 4,4-dimethyloxazoline (DMOX) derivatives. We identified seven out of 13 possible structures of hydrogenated CFAMs formed from EPA, and nine out of 16 possible structures of CFAM formed from DHA. Major CFAMs from both EPA and DHA were cyclohexyl isomers. All possible cyclohexyl isomers were found but only nine out of 18 of the cyclopentyl isomers were present in concentration sufficient for identification. Chemical mechanisms involved in the formation of polyunsaturated LC-PUFAs have been investigated. The results have shown that general principle involved in the cyclization of LC-PUFAs is same as that for the thermal cyclization of oleic, linoleic and alpha-linolenic acids.     

Syntheses of some tetralones related to tetracyclines

Syntheses of 5-chloro-8-methoxy-1-tetralone (XIV), 6,8-dimethoxy-1-tetralone (XIX), 2-carbethoxy-6,8-dimethoxy-1-tetralone (VI), 3-(2′-chloro-5′-methoxybenzyl)-6,8-dimethoxy-1-tetralone (III) and 2-carbethoxy-3-(2′-chloro-5′-methoxybenzyl)-6,8-dimethoxy-1-tetralone (IV) are reported. The mode of cyclization with polyphosphoric acid of I and related compounds is described.     

Syntheses of some indazoles structurally related to equilenin

This study reports the complete synthesis and characterization of the 15, 16-diazaequilenin derivative 10,11-dihydro-3H-naphth[1,2-g]indazol-7-ol ( 2b ) as well as the methyl ether 2a of the above compound and the novel “model” compound 4,5-dihydro-1H-benz[g]indazol-7-ol ( 3b ). Indazoles 2a and 3a have demonstrated in vitro activity against a variety of microorganisms.     

某些含氧酸的酸强度与量化参数的相关性

本文利用从头计算法, 采用STO-3G基集计算了某些含氧酸分子的电子结构, 它们的标准几何构型取自已知的实验数据. 将氢、氧原子上的总电荷密度以及氧原子上的亲电子超离域度与实验测得的酸性离解常数相联系, 应用多元回归法, 得到了较好的线性关系.     

Fluorescence high-performance liquid chromatography of arachidonic, eicosapentaenoic and some other higher fatty acids in ovary of several fishes

Summary A highly sensitive and selective fluorescence high-performance liquid chromatography using 9-anthryl-diazomethane as a pre-labelling reagent was applied to the simultaneous microanalysis of arachidonic and eicosapentaenoic acids, and some other higher fatty acids at nanogram level in ovary of several tropical adult fishes taken at Rabaul of New Britain. An existing tendency of arachidonic and eicosapentaenoic acids as precursor of prostaglandins in the generative organ of the fishes, has been revealed.

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Fluorescenz-HPLC von Arachidonsäure, Eicosapentansäure und einigen anderen höheren Fettsäuren im Ovarium verschiedener Fischarten

     

A simplified method for analysis of polyunsaturated fatty acids

Background  

Analysis of fatty acid composition of biological materials is a common task in lipid research. Conventionally, preparation of samples for fatty acid analysis by gas chromatography involves two separate procedures: lipid extraction and methylation. This conventional method is complicated, tedious and time consuming. Development of a rapid and simple method for lipid analysis is warranted.     

Syntheses and biological evaluation of phosphoryl-containing polyunsaturated fatty acid derivatives as hypolipidemic agents

A series of novel compounds phosphoryl-containing polyunsaturated fatty acid derivatives n-(diisopropoxy-phosphonamide)-alkyl ester (2a–2o) have been synthesized and evaluated for lowering hypolipidemia activities. Amongst all the synthesized compounds, compound 2d, 2h, and 2m showed significant lowering of triglyceride (TG) by 47.37%, 45.88%, and 45.69%, respectively, in triton induced hyperlipidemic in mice. Furthermore, compound 2d showed potent antihyperlipidemic activity and was found to decrease the plasma total cholesterol levels (TC) by 53.3%, TG by 29.3%, in high-fat diet induced hyperlipidemic in mice.     

Analysis of polyunsaturated fatty acids in blood serum after fish oil administration.

Free and total fatty acids in the blood serum of patients with hyperlipoproteinemia have been analysed as their methyl esters by capillary gas chromatography using an FFAP column. In one-step reactions the free fatty acids in serum react with methanol-acetyl chloride (50:1, v/v) at 25 degrees C, the total fatty acids (free plus esterified) are transesterified with methanol-toluene-acetyl chloride (8:2:1, v/v) at 100 degrees C. The quantification of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is based on an internal standard (13,16,19-docosatrienoic acid) and on calibration standards. Under normal diet the concentrations of EPA and DHA are as follows (mean +/- S.D., n = 27): free EPA, 0.2 +/- 0.1 mg/dl; free DHA, 0.6 +/- 0.2 mg/dl; total EPA, 3.6 +/- 2.1 mg/dl; total DHA 11.4 +/- 3.1 mg/dl. Under a fish oil intake of 9 g per day, free and total EPA concentrations rise by ca. five- to six-fold, and free and total DHA concentrations by ca. two-fold.     

Oxidation stability of eicosapentaenoic and docosahexaenoic acid included in cyclodextrins

We have proposed a novel method for complexing of the -3 polyunsaturated fatty acids (PUFA), such as eicosapentaenoic and docosahexaenoic acids, with cyclodextrin as dry powders by a twin-screw kneader. The effect of various oxidation conditions on powdery PUFA were investigated. Further, the powdery PUFA developed was employed in the preparation of fish meal as a functional sea food paste.     

Some aspects of the stereochemistry and nomenclature of polyunsaturated hydroxy fatty acids

When the D, L (but not the R, S) nomenclature is used, general laws are observed in the stereochemistry of lipoxygenase oxidation reactions and in the formation of epoxides from hydroperoxides of polysaturated hydroxy fatty acids. In both cases the formation of a C-O bond is coupled with the stereoselective elimination of a hydrogen atom, and the chiral and prochiral carbon atoms have identical configurations. The use of the D, L nomenclature in the polyenic hydroxy fatty acid series appears preferable to that of the R, S nomenclature.     

Some aspects of the stereochemistry and nomenclature of polyunsaturated hydroxy fatty acids

When the D, L (but not the R, S) nomenclature is used, general laws are observed in the stereochemistry of lipoxygenase oxidation reactions and in the formation of epoxides from hydroperoxides of polysaturated hydroxy fatty acids. In both cases the formation of a C-O bond is coupled with the stereoselective elimination of a hydrogen atom, and the chiral and prochiral carbon atoms have identical configurations. The use of the D, L nomenclature in the polyenic hydroxy fatty acid series appears preferable to that of the R, S nomenclature.A. L. Mndzhoyan Institute of Fine Organic Chemistry, Academy of Sciences of the Armenian SSR, Erevan. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 622–623, September–October, 1985.     

Chemical synthesis of deuterium-labeled and unlabeled very long chain polyunsaturated fatty acids

First syntheses of a deuterium-labeled very long C34-containing polyunsaturated fatty acid, 34:5n5, and three other unlabeled very long chain C30-32 containing polyunsaturated fatty acids are reported. These syntheses were achieved by coupling chemically modified C22- and C20-containing polyunsaturated fatty acids with carbanions derived from arylalkyl sulfones, followed by sodium amalgam-mediated desulfonylation.     

Dicranenones — A new class of C18 polyunsaturated fatty acids

In this review paper we consider questions of the occurrence in nature and the biosynthesis and total chemical synthesis of the dicranenones — new cyclopentanoid C₁₈ polyunsaturated fatty acids. A critical evaluation of the stereochemical assignments in this series of compounds is given. Institute of Bioorganic Chemistry, Belorussian Academy of Sciences, Minsk. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 607–622, November–December, 1992.     

尿素包合法分离蚕蛹油中多不饱和脂肪酸

蚕蛹是缫丝副产品,我国每年副产近20万吨干蛹[1].蚕蛹中油脂含量相当丰富,约占蚕蛹干基的25%～29%,且油脂总量的71.0%为不饱和脂肪酸,这些不饱和脂肪酸在人体内可合成二十碳五烯酸及二十二碳六烯酸,与鱼油中的EPA,DHA具有相似的抗衰老、健脑益智的功能,能维持正常的肾脏功能,治腰背疼痛、肌肉无力,预防动脉硬化、血脂升高等血栓疾病[2].     

beta-Hematin (hemozoin) mediated decompostion of polyunsaturated fatty acids to 4-hydroxy-2-nonenal

beta-Hematin is an important heme metabolite of malarial infection. Its role as an agent mediating the formation of the reactive electrophile 4-hydroxynonenal (HNE) from polyunsaturated fatty acids was investigated. In vitro formation of HNE was found to be facilitated by the presence of hemozoin in a concentration-dependent fashion. The reactivity of HNE derived from reaction with beta-hematin was confirmed through its ability to form protein adducts on myoglobin.